Transplantation

transplantation

The artificial removal of part of an organism and its replacement in the body of the same or of a different individual.

To remove a plant from one location and replant it in another place.

Transplantation

the grafting of tissues and organs.

Animals and man. Transplantation in animals and man is the implanting of organs or the grafting of tissues to repair defects and stimulate regeneration. Transplantation is also used in cosmetic surgery and tissue therapy and for experimental purposes. The material is taken from one individual (the donor) and is transferred to another (the recipient, or host). Different types of transplantation are autotransplantation, or transplantation when the donor and the recipient are the same individual; homotrans-plantation, or transplantation from one individual to another of the same species; heterotransplantation, when the donor and recipient are of different species of the same genus; and xenotrans-plantation, when the donor and recipient belong to different genera, families, or orders. All types of transplantation except autotransplantation are varieties of allotransplantation.

In homotransplantation of such vital organs as the kidneys and heart, the transplanted material may be rejected by the recipient. When repeated grafts are transplanted from the same donor, the later grafts are damaged or rejected more rapidly than the earlier grafts; this is proof of the immunological nature of the damage and rejection of homografts.

Homografts may be retained permanently by the recipient if the donor and host are identical twins or are members of a clone; if living donor cells are first introduced into the recipient, thus causing the recipient to tolerate the donor’s tissues; or if the recipient is subjected to whole-body irradiation. Translanted corneas that replace clouded corneas remain transparent, since no blood vessels grow into them. Homografts of bone and of blood vessels do not remain viable, but they serve as a scaffolding that facilitates regeneration of the recipient’s own bone and vascular tissues.

Heterotransplantation and xenotransplantation of such parts of the body as joints is seldom attempted.

Transplantation as a scientific technique was first attempted by the English scientist J. Evelyn, who in 1662 grafted a rooster’s spur onto its comb. Later experiments with autotransplantation and homotransplantation in embryos facilitated the study of the central nervous system, the eye, the inner ear, and the extremities and affirmed the influence of some parts of the embryo on others. It was learned that when a part of the ectoderm from the site on the dorsal side of a vertebrate embryo where the neural plate develops was grafted onto the ventral side, the results differed according to the embryo’s stage of development. In the later stages of development, the grafted part developed into a neural plate at the new site, and in the earlier stages the grafted part formed only epithelium.

Transplantation has also facilitated the study of such aspects of postembryonic development as the metamorphosis of amphibians and the functioning of the glands of internal secretion, for example, the pituitary and the gonads. By transplanting parts of a pituitary to animals whose pituitaries had been removed, the hormones secreted by this gland were isolated. Transplantation of the gonads has facilitated the study of the development of the secondary sex characteristics. The knowledge acquired through the application of transplantation techniques has also permitted a more comprehensive study of regeneration, and in particular of the tissue components in organs that are capable of regeneration, such as the tail and extremities of caudate amphibians. The joining of two parts more or less identical in size, for example, the halves of two different organisms, is of great scientific importance. Such transplantations are called grafts. The surgical union of two organisms is called parabiosis. The branch of medicine that studies transplantation is called transplantology.

P. IA. BLIAKHER

Medical transplantology. Medical transplantology developed as a branch of surgery and in contrast to surgery uses the method of free plastic surgery, or the transplanting of unattached tissues and organs.

References to the transplantation of organs and tissues are found in Greek mythology, in the Christian legends of Saints Cosmas and Damian, and in folktales of the early Middle Ages. A legend recounts that the Chinese surgeon Hua T’u (second century A.D.) removed diseased internal organs and replaced them with normal ones. Scientific transplantology was founded in the early 19th century with the publication of the clinical and experimental observations of the Italian surgeon G. Baronio (1804) and of the German surgeon K. Bünger (1823).

The publications of N. I. Pirogov, among them Plastic Operations in General and Rhinoplasty in Particular (1835), and those of Iu. K. Shimanovskii, including Operations on the Surface of the Human Body (1865), were important contributions to the development of medical transplantology in Russia. Progress in experimental medicine and in such surgical procedures as anesthesia, antisepsis, and asepsis prepared the way for the use of transplantation in clinical practice. Further contributions to the development of transplantation in Russia were made by N. Shtraukh (1840) and N. Feigin (1867), pioneers in the transplanting of corneas, and by V. Antonevich (teeth transplants, 1865), K. M. Sa-pezhko (transplants of mucous membrane, 1892), and many others.

The methods developed for transplanting bone by the French surgeon L. Ollier (1858) and for transplanting skin by the Swiss surgeon J.-L. Reverdin (1869) were further developed by the Russian scientists E. I. Bogdanovskii and P. I. Karpinskii (1861), S. M. Ianovich-Chainskii (1870), P. Ia. Piasetskii (1870), and A. S. Iatsenko (1870). S. S. Ivanova used the skin of cadavers for transplants (1890). The experimental and clinical grafting of joints was first performed in Russia, by Iu. R. Penskii (1893) and P. I. Bukhman (1907), respectively. Other transplantation procedures first conducted in Russia were the grafting of the cartilage of the concha auriculae in rhinoplasty (K. P. Suslov, 1897), of the anterior part of the eye (A. F. Shimanovskii, 1906), of the fascia (V. L. Bogoliubov, 1908), and of fat to repair defects in brain matter (S. I. Spasokukotskii and E. I. Golianitskii, 1913).

One of the first successful organ transplants in Russia was performed by V. G. Grigor’ev, who successfully transplanted an ovary with restoration of functions (1897). The methods of suturing blood vessels developed by the French surgeon A. Carrel (1902) prepared the way for the transplanting of organs together with their blood supply. Advances in infection and noninfection immunology, and particularly in transplantation immunology, were of great importance for the development of transplantation.

Numerous achievements have testified to the successful development of transplantation in Russia and the USSR. Studies on the viability of various tissues were made by P. I. Bakhmet’ev (1899–1912), F. A. Andreev (1913), and N. P. Kravkov (1920–24). A. A. Kuliabko removed from a newly deceased corpse a human heart that survived for 20 hours (1902). The experiments of V. N. Shamov (1928) and of S. S. Iudin (1930) on blood transfusion proved that cadaver tissue (in the form of fibri-nolysed blood) could be transplanted. V. P. Filatov and N. M. Mikhel’son successfully transplanted corneas (1931) and cadaver cartilage (1935), respectively. A 1937 decree of the Council of People’s Commissars of the USSR provided a legal basis for the removal and use of cadaver tissues and organs.

In 1933 the Soviet surgeon Iu. Iu. Voronoi performed the first clinical transplant of a kidney from a cadaver, thus initiating modern transplantology and the grafting of vital organs. The intensive development of transplantation was an outgrowth of the scientific and technological revolution and of advances in biomedical disciplines. Of particular importance were the invention of the artificial kidney (1944), experiments in grafting vital organs conducted by N. P. Sinitsyn (1945) and V. P. Demikhov (1947), and the studies on tissue incompatibility and acquired im-munotolerance carried out by P. B. Medawar (1953). Important research on transplantation antigens was conducted by the French scientist J. Dausset (1958), and the effect of immuno-depressants was studied. The first clinical transplants of the liver, lungs, and pancreas were performed by the American surgeons T. Starzl (1963), J. Hardy (1963), and R. Lillehei (1966), respectively, and the first clinical transplant of the heart was performed by C. Barnard (Republic of South Africa, 1967).

According to official statistics, as of Jan. 1, 1975, there were 301 kidney transplant centers worldwide which by Jan. 1, 1976, had performed 23,919 transplants, the longest surviving 19 years. There were 64 heart transplant centers (296 transplants; longest survival, seven years, one month), 41 liver transplant centers (254 transplants; longest survival, six years), and 15 pancreas transplant centers (47 transplants; longest survival, three years, six months). Kidney transplants have proved to be the most effective clinically. Important advances have been made in repeated and multiple kidney transplants. The first successful kidney transplant operation in the USSR was performed by B. V. Petrovskii in 1965. As of Mar. 1, 1976, there were 15 kidney transplant centers in the USSR that had performed some 1,500 transplants. The All-Union Scientific Research Institute of Clinical and Experimental Surgery and the Institute of the Transplantation of Organs and Tissues of the Ministry of Public Health of the USSR are the USSR’s leading research centers in the field of kidney transplants.

Modern transplantology focuses on transplantation immunology, clinical transplantation, the maintenance of viability in organs and tissues, and experimental transplantology. Efforts are being made to create artificial organs, especially an artificial heart, liver, and pancreas. The International Transplantation Society was founded in 1966, and international congresses on transplantation have been held since that year. Journals in the field include Transplantation (Baltimore, Md., since 1963) and Transplantation Reviews (Copenhagen-Baltimore, since 1969).

Plants. In plants, transplantation is the grafting of part of a plant or of a plant organ to another part of the same or a different plant. Cell division is activated and there is increased tissue growth at the site of the graft owing to the effect of wound hormones; a callus often forms. Examples of grafting in plants for practical purposes include the grafting of certain plants onto the roots of others that are more hardy, and the rooting of poorly rooted cuttings. Grafting can alter the time at which plants flower and bear fruit and can also improve the quality of fruit and increase the yield. Changes in the scion that are caused by the stock are not hereditary and are not transmitted in the scion’s seeds during reproduction.Plant grafting is an important method of studying the hormonal regulation of plant growth and development. Experiments in which the buds of some plants were grafted onto callused tissue have shown that buds are a source of auxin, which causes conducting tissue to form in the callus. The same method has shown that under conditions favorable to flowering, photoperiodically sensitive plants form substances which migrate from their leaves or flowers into nonflowering stock plants (sometimes of different genera or species). In the lower plants, particularly those that are unicellular, the organelles may also be transplanted. In an experiment that studied the role of the nucleus and cytoplasm in the structure of the unicellular alga Acetabularia, several nuclei were introduced into a single cell and, in addition, parts of various species were grafted together. With the use of centrifugation it was possible to separate the cytoplasm and cell membrane and to assemble a cell from the cytoplasm, membrane, and nucleus of plants belonging to different species, as well as of plants in varying functional states.

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